1. Field of the Invention
The invention relates to an oil bailer apparatus for use in bailing oil from an oil well as well as removing natural gas.
2. Description of Related Art
Oil bailers are known in the art. However, previous methods of extracting oil, in particular, the bailers and controls used with such bailers fail to differentiate between oil and water in a given well. The problem of non-differentiating between water and oil is especially experienced in low producing wells.
Known related art includes the solid state control system for the oil bailer depicted in U.S. Pat. No. 4,516,911 to Senghaas et al., the oil bailer depicted in U.S. Pat. No. 4,368,909 to Alexander, Jr., and the automated bailer depicted in U.S. Pat. No. 4,037,662 to Bowling.
None of the devices in the above references solve the problem of differentiating between water and oil, especially in low producing wells, and at the same time, address the recovery of natural gas from the oil pumping operation.
It is therefore the intention of this invention to provide an improved oil bailing system, which differentiates between oil and water in a given well, removes only oil, capable of operating on 5,000 foot wells and operates at the removal rate of 25-35 barrels per day. It is also an object of the invention to accomplish the differentiation between water and oil by the incorporation in the system design of a programmable logic control (PLC) to operate the mechanical system portion of the apparatus, and to provide means for accessing data from multiple field sites through a server from a website. This will be used to gather and supply daily data to the manufacture and customer which includes daily output of gas and oil, system error data and daily activities.
It is also an object of the invention to provide a generally 100 percent sealed apparatus so that a vacuum can be applied to recover the natural gas. Most conventional pump jacks and other oil recovery systems use high energy consuming methods and pump out polluted water that must be processed and re-injected back into the oil column, and most allow oil to spill out on to the ground surface. A sealed apparatus will solve these problems.
The invention which is an apparatus and system control for the removal of fluids and gas from a well includes means for removing fluids from a well bore, the well bore having a well casing therein, and the fluids being substantially oil and water.
The invention further includes a temporary storage tank which has an upper end and a lower end, the lower end being in fluid communication with the well casing. The lower end of the temporary storage tank further includes a first bailer tube guide pipe having means for mechanically coupling the first bailer tube guide pipe at one end to the well casing. The first bailer tube guide pipe sealingly extends into an interior of the temporary storage tank.
The means for mechanically coupling the first bailer tube guide pipe at the one end to the well casing further includes natural gas recovery means for recovering a natural gas exhausting from the well casing.
The first bailer tube guide pipe extends a predetermined height into the interior of the temporary storage tank and has tank valve means for selectively opening and closing an opening of the first bailer tube guide pipe.
The upper end of the temporary storage tank is mechanically coupled to a second bailer tube guide pipe, which sealingly extends a predetermined depth into the interior of the temporary storage tank. The second bailer tube guide pipe has means for mechanically coupling the second bailer tube guide pipe to a third bailer tube guide pipe of predetermined length and axially aligned with the second bailer tube guide pipe. The second and third bailer tube guide pipes are also axially aligned with the first bailer tube guide pipe. Each of the first, second and third bailer tube guide pipes have internal diameters sized to allow a free up and down travel of a bailer tube, also referred to herein as a bailer housing, therein.
Included is pulley means proximate an upper end of the third bailer tube guide pipe over which a cable wire attached to a first end of the bailer tube is run. An opposite end of the cable wire is attached to the means for removing fluids from the well bore, which is typically a driven winch means for pulling the bailer tube out from the well casing and for lowering the bailer tube into the well casing.
A second end of the bailer tube typically has a bailer housing valve, typically a two way direct current (DC) valve, for selectively capturing a column of oil inside the well casing when said bailer tube is lowered therein, and for discharging said captured column of oil into the temporary storage tank when said bailer tube is raised out of the well casing. The bailer housing valve is in electrically operative communication with a programmable logic controller (PLC) means, which is typically an electrical enclosure housing with various processing capabilities which include a micro-processing unit typical of computers, gauges for monitoring various desired operating parameters such as flow rates of oil and gases, oil level in temporary storage tank, pressures, bailer tube travel speeds, etc., actuator switches for activating and controlling the winch and pumping means to empty the temporary storage tank, among other functions. That is, the PLC means is a means for monitoring, operating and controlling the apparatus and for translating readable information to obtain and record operational parameters.
The second end of the bailer tube also includes oil and water sensor means for differentiating between the water and oil inside the well casing as the bailer tube descends therein. The oil and water sensor means defines a top and bottom of a well casing column of oil, as well as the top of water, which essentially coincides with the bottom of the oil column.
The cable wire is preferably a multiple conductor cable wire which is in electrical communication between the bailer housing valve and the driven winch means. The cable wire is also electrically and operatively connected to the PLC means.
The PLC means calculates changes in the size of the oil column, decreasing or increasing the adjustable travel speed of the bailer tube to recover an optimum oil recovery without depleting the oil column. Once correctly positioned at the optimum depth inside the well casing, the bailer housing valve is closed thereby capturing oil inside said bailer tube and the bailer tube is elevated so that bailer housing valve, also referred to herein as bailer valve, is inside and at the upper end of the temporary storage tank at which location, the tank valve means for selectively opening and closing an opening of the first bailer tube guide pipe is closed after which the bailer valve is opened and the captured oil in the bailer tube is discharged into the temporary storage tank.
The tank valve means for selectively opening and closing the opening of the first bailer tube guide pipe, the driven winch means, the oil and water sensor means are also each in electrical and operative communication with the PLC means.
The PLC means controls and monitors a speed of the bailer tube at each location of the bailer tube inside the well casing as the bailer tube is being lowered into and elevated out of the well casing.
In a practical application of the invention, the oil and water sensor means is typically a ground probe switch located at a leading edge of the bailer tube which is activated when a conductive path between a terminal of said ground probe switch is established as the terminal contacts the oil and water under the oil in the well casing thereby defining the top of the oil column, and the bottom of the oil column which also coincides with the top of the water in the well casing.
The driven winch means preferably comprises encoder means in electrical communication with the PLC means for converting a rotation of the winch means into a linear motion to determine a speed of the bailer tube traveling inside the well casing and a location within said well casing. The tank valve means for selectively opening and closing an opening of the first bailer tube guide pipe is a typically a slide gate valve or ball valve.
The temporary storage tank comprises means for monitoring the level of captured oil in the temporary storage tank; and actuation means operatively connected to pumping means for pumping the captured oil from the temporary storage tank to a predetermined storage location.
The means for mechanically coupling the first bailer tube guide pipe to the well casing is preferably a tee-fitting;
although it may be a manifold designed to couple the well casing and the first bailer tube guide pipe. The advantage of a teed fitting or equivalent manifold is to provide an outlet for recovered natural gas and for installing appropriate monitoring devices such as a flow meter and volume gauge as described below.
The natural gas recovery means further comprises means for monitoring one of a flow rate of natural gas exhausting from the well casing, a volumetric quantity of natural gas exhausting from the well casing, and a combination thereof, wherein a corresponding natural gas recovery means data from the means for monitoring one of the flow rate of natural gas exhausting from the well casing, the volumetric quantity of natural gas exhausting from the well casing, and the combination thereof is transmitted to the PLC means.
The means for mechanically coupling the first bailer tube guide pipe to the well casing typically further includes a swivel flange means for aiding in an alignment and installation of the temporary storage tank to the well casing. The means for mechanically coupling the second bailer tube guide pipe to the third bailer tube guide pipe is typically flange means. Gasketed flanges provide excellent mechanical sealing properties in outdoor environmental related industries.
The invention further includes support and guide means at the upper end of the third bailer tube guide pipe for supporting and guiding the wire cable through third bailer tube guide pipe, which is typically a stuffing box and sheave assembly or grease head through which the wire cable is run.
A proximity sensor switch is located proximate the upper end of the third bailer tube guide pipe. The proximity sensor switch is in electrical communication with the PLC means and provides means for decreasing a travel speed of the bailer tube being raised from the well casing. A back up proximity sensor switch is located in a predetermined spaced apart relationship with the proximity sensor switch, typically about 4-8 inches above the primary proximity sensor switch. This back up proximity sensor switch also provides means for decreasing the travel speed of the bailer tube should the proximity sensor switch fail, the back up proximity sensor switch being therefore also in electrical communication with the PLC means.
The PLC means monitors a top of the oil column location within the well casing as well as a bottom location of the oil column within the well casing, the bottom location corresponding to a location of the top of the water column within the well casing.
The optimum depth in the well casing of the second end of the bailer tube for capturing the column of oil without water is an intermediate location, generally half way but any desired location can be selected, between the location of the top of the oil column and above the location of the bottom of the oil column.
In a typical balanced operation sequence the PLC means operationally opens the bailer valve and the tank valve means for selectively opening and closing the opening of the first bailer tube guide pipe, starts the lowering of the bailer tube into the well casing at a predetermine adjustable speed, and increases the adjustable speed to a predetermined adjustable travel speed. The bailer tube is allowed to descend toward the location of the top of the oil column within the well casing, as the adjustable travel speed is decreased at a predetermined location, generally a stored logging depth, above the location of the top of the oil column. The second end of the bailer tube is allowed to enter into the oil column and stop descending at the optimum depth, at which point the bailer valve is closed after a predetermined preset dwell time to capture oil within the bailer tube. The bailer tube then starts elevating through the well casing at an ascending adjustable speed progressing to an ascending adjustable travel speed, slows down as the ascending adjustable travel speed as the bailer tube enters the temporary storage tank. The bailer tube then stops when the second end of the bailer tube is above the tank valve means for selectively opening and closing the opening of the first bailer tube guide pipe at which point the tank valve means for selectively opening and closing the opening of the first bailer tube guide pipe is closed. The bailer valve is then opened for a predetermined top dwell time thereby discharging the captured oil in the bailer tube inside the temporary storage tank, after which dwell time, the two way DC valve is closed after the captured oil has been discharged into the temporary storage tank. The above operational process is then repeated as desired.
The PLC means also activates the actuation means operatively connected to the pumping means for pumping the captured oil from the temporary storage tank when said temporary storage tank accumulates a predetermined level of captured oil.
In a typical logging process or first sequence operation, the PLC means operationally opens the bailer valve and the tank valve means for selectively opening and closing the opening of the first bailer tube guide pipe, starts the lowering of the bailer tube into the well casing at a predetermine adjustable speed, and increases the adjustable speed to a predetermined adjustable travel speed. The bailer tube is then allowed to descend toward the location of the top of the oil column within the well casing. The adjustable travel speed is then decreased at a predetermined location, the pre-set stored logging depth, above the location of the top of the oil column, allowing the second end of the bailer tube to enter into the oil column and stop descending when the oil and water sensor at the second end of the bailer tube is activated. The defined top of the water and bottom of the well casing column of oil location is stored for future use as the control system calculates changes in the size of the oil column, decreasing or increasing the adjustable travel speed of the bailer tube to recover an optimum oil recovery without depleting the oil column. The two way DC valve is then closed after a predetermined preset dwell time to capture oil within the bailer tube. The bailer tube then starts elevating through the well casing at an ascending adjustable speed progressing to an ascending adjustable travel speed. The ascending adjustable travel speed then slows down as the bailer tube enters the temporary storage tank, and the bailer tube stops when the second end of the bailer tube is above the tank valve means for selectively opening and closing the opening of the first bailer tube. The tank valve means for selectively opening and closing the opening of the first bailer tube guide pipe guide pipe closes, the bailer valve opens for a predetermined top dwell time thereby discharging the captured oil in the bailer tube inside the temporary storage tank. The bailer valve then closes after the captured oil has been discharged into the temporary storage tank, and the above logging process is then repeated as desired.
The PLC means is also capable of monitoring an accumulated level of oil in the temporary storage tank, gaseous pressure, oil pressure in the well casing and temporary storage tank using corresponding pressure sensor means. Further, the PLC means may also monitor the hydraulic winch level using a sensor as well as monitor the tension in the cable wire.
In another embodiment of the invention, the PLC means for one or more field sites is operatively connected with one or more Field Communicator PCs, each including a dial up modem, ISDN connector and an FTP router, which in turn communicates with a data base server PC. This server is accessible through a website in which data collection, reporting, analysis and visualization displays can be viewed by a customer base. In addition, each PLC means is operatively in communication with a paging system which outputs data to a field service department.